The way I would tie it in is: A group of bankers seeking to get the Governor elected, crashes the economy in order to create "order out of chaos." While investigating corruption in New York the former Marine (now a contractor for a security firm) uncovers the plot, thus the plotters decide to pin the forth coming attacks on him to silence him forever.
It's basically taking the premise of a number of conspiracy theories and playing them out. It wouldn't be a movie - their be no time at all it would be more suited as a TV series, on premium cable, HBO and the like.